The present invention relates generally to radar systems, and particularly to dipole or monopole antennas useful as radiating elements for radar arrays.
It is known that antenna applications such as Integrated Friend or Foe (IFF) or Secondary Surveillance Radar (SSR) systems have been implemented with long range Primary Surveillance Radars (PSR). Such systems include the AN/TPS-59(V3), AN/TPS-59(M34), AN/FPS-117 and TPS-117 radar systems, for example.
Such radar systems use a separate linear or planar array of radiators as an IFF or SSR antenna. The IFF or SSR antenna is typically physically bolted to the upper surface of the PSR antenna structure. This can be seen in FIGS. 1A, 1B and 1C, which illustrate Prior Art SSR antenna arrangements 150 bolted to the upper surface of a PSR antenna structure 100. FIG. 1A illustrates an exemplary SSR/PSR arrangement for the AN/TPS-59 system manufactured by Lockheed Martin Corporation. FIG. 1B depicts an exemplary embodiment of TPS-117 Tactical Transportable Radar System, while FIG. 1C shows a transportable model of the FPS-117 Long Range Solid State Radar System. In the case of the AN/TPS-59 and TPS-117 radars, the IFF or SSR antenna is a linear array of dipoles, cavity backed dipoles, or patches which must be physically removed from the PSR in order to relocate or transport the system. The time required to remove or replace the IFF or SSR antenna and the space required to stow it add significant problems to march order configuration, deployment time and transportation requirements, for example.
In the case of the FPS-117 radar system, many of the SSR antennas are large planar arrays which require a separate supporting structure. Such support structures may weigh up to 700 pounds (lbs)., and add over 5 feet (ft) to the overall height of the system. FPS-117 radars with large planar arrays, for example, require much larger radomes (if used) than those with linear arrays. This, too, adds to the overall size and cost of the system.
Integrated IFF antennas also exist in other Tactical Planar Array Radars (TPLARs), such as the AN/PPQ-2 PSTAR Radar. However, in the case of the AN/PPQ-2 system, the IFF antenna is a separate linear array of vertically polarized dipoles situated inside the radome case above the PSR array, thus also adding to the overall size of the system.
It is an object of the present invention to utilize a linear or planar array of vertically polarized dipole or monopole radiators for an IFF/SSR antenna. The array of radiators is fed by stripline corporate feed or row feed structures which provide the Sum and Side Lobe Suppression (SLS) Channels required for SSR operations. The linear arrays of vertical radiators are interleaved with the existing linear arrays which comprise the PSR antenna, thereby providing two antenna functions within a single antenna aperture. In a primary antenna system comprising a plurality of planar arrays of radiating elements, each planar array separated via a conductive septum, a method of forming an integrated antenna system, the method comprising interleaving portions of a secondary antenna between said plurality of planar arrays by replacing at least a portion of each the conductive septum with a stripline corporate feed using vertically polarized dipoles or monopoles defining a secondary antenna.
In folded, integrated antenna system for use on a vehicle comprising a primary radar comprising a plurality of planar arrays of radiating elements, each planar array comprising a central portion and adjacent wing portions, pivotably coupled to the central portion to fold inward and outward over said central portion and a secondary radar comprising a plurality of planar arrays of vertical radiators interleaved with the plurality of planar arrays of radiating elements and coupled via a stripline feed structure for receiving signal information, and a conductive wing portion substantially aligned with a corresponding one of the adjacent wing portions of the planar arrays and operatively coupled thereto, the conductive wing portion having a plurality of slots therein, each of the slots aligned with a corresponding one of the vertical radiators of the secondary radar to permit folding of the wing portions of the array and the associated conductive wing portion without interfering with the vertical radiators.